State Snapshot

The snapshot feature enables you to capture and restore the state of all stores currently in scope or a selected subset of stores within your application. This can be particularly useful for scenarios where you need to save and later revert application state, such as when performing a rollback or in response to user actions.

Snapshot works with both regular stores and immutable stores.

Usage

A snapshot is a representation of the application state at a specific point in time. It includes a timestamp indicating when the snapshot was created and a restore method to revert the application state to the captured snapshot.

Snapshot Creation

The createSnapshot function is used to generate a state snapshot. It accepts a variable number of store instances or store class types as parameters. If no stores are provided, the snapshot will include all stores.

import { createSnapshot } from 'signalstory';

// Capture all stores
const snapshot1 = createSnapshot();

// You can use the store class types
const snapshot2 = createSnapshot(BookStore, UserStore);

// You can use store instances
const store1 = new Store<string>({ initialState: '' });
const store2 = new Store<string>({ initialState: '' });
const snapshot3 = createSnapshot(store1, store2);

// Or mix
const snapshot4 = createSnapshot(store1, BookStore);

Snapshot Restoration

To restore the application state to a specific snapshot, call the restore method on the created snapshot. All captured stores will rollback their respective state. The snapshot can be reused and is destroyed only when garbage collected.

snapshot.restore();